Cylinder lock



Sept. 21, 1937. G. B. PICKOP 2,093,925

CYLINDER LOCK Filed May 18, 1936 2 Sheets-Sheet 1 I" II III I E III I! I, [-1 I i E 27 2e 25 zm 11 Lilli!llllllll|lllllm|||l G. B. PICKOP CYLINDER LOCK Sept. 21, 1937.

Filed May 18, 1936 2 Sheets-Sheet 2 Patented Sept. 21, 1937 UNITED STATES CYLINDER LOCK George B. Pickop, New Haven, Conn, assignor to The New Haven Vibrator Company, Inc., New Haven, Conn., a corporation of Connecticut Application May 18, 1936, Serial No. 80,237

4 Claims.

This invention relates to cylinder locks, and more particularly to looks of the so-called pin tumbler type, in which a key barrel or key plug is rotatably mounted within a cylinder or casing, and cooperating pins and drivers are mounted in bores in the cylinder and key plug to prevent the turning of the latter within the cylinder except when the breaks between the pins and drivers are aligned with the surface of the key plug by the proper key.

Locks of this character are usually provided with a fiat key, which ordinarily has the pin tumbler notches cut into one edge, the other edge being left straight and flat. The keyhole is also of generally flat shape, and as a result the key may only be inserted in the key slot in one position. It is sometimes difiicult, particularly at night, for the user of the key to find the slot, that is, to properly position the key without a considerable period of trial and error so that it will enter the slot.

Moreover, flat keys of the type described usually have ward slots milled therein, which slots are designed to receive ward projections provided in the key barrel. This increases the number of different combinations which can be secured with a given number of tumblers in the lock, and also provides against any but a key of a particular type being inserted in a given look. It also, however, has the disadvantage of making it more diificult to insert the key, as the latter must not only be aligned with the slot but must be inserted in the proper position for the wards in the key plug to be received in the slots in the key.

The present invention is designed to provide a cooperating lock and key such that the key may be initially inserted within the key barrel in any position, without regard to the position of the pin tumblers, whereby it will be relatively easy for anyone to insert the key into the look, even in the dark, and after the key is once inserted it may be rotated to the proper position to operate the lock, which position will be readily found without difiiculty, this rotation occurring after the key has been initially inserted in the keyhole. The key may be inserted substantially without any attention on the part of the user, and therefore may be readily inserted in the dark without the usual trial and error operations necessary to find. the keyhole.

One object of the invention is the provision of a cooperating lock and key such that the key may be inserted into the opening provided therefor with slight attention on the part of the operator.

Another object of the invention is the provision of a cooperating lock and key of such a character that the key may be readily inserted within the lock in any position of the key, and thereafter rotated to its operating position.

A still further object of the invention is the provision of a lock having a round or cylindrical key opening and a key of corresponding shape, so

that the latter may be initially inserted into the To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the drawings: A Fig. 1 is a front elevational view ofa lock embodying my invention;

Fig. 2 is a sectional view of the lock showing the 1" key in place within the key opening;

Fig. 3 is an elevational view of therear face of the lock cylinder;

Fig. 4 is a sectional View on line 47-4 of Fig. 2;

.Fig. 5 is a sectional View on line 5-i-5 of Fig. 2;

Fig. 6 is an elevational view of a key of modified form which may be used with my lock;

Fig. 7 is a front elevational view of a further modification of my invention;

Fig. 8 is a sectional view of the lock shown in Fig. '7;

Fig. 9 is a sectional view online and Fig. 10 is a top plan View of the key employed in the lock shown in Figs. 7 to 9.

To illustrate a preferred embodiment of ,my invention I have shown a lock of the pin tumbler type comprising a cylinder I0 and a key barrel or plug l l. The cylinder is providedwith a series 9-9 of Fig.8;

of chambers l2 containing the drivers I3; which are urged toward the key plug by the springs I4 in the usual manner.

The key plug is provided with a key opening of circular shape throughout the greater part of its length. Communicating with this key opening are pin tumbler chambers l6, within. which the pin tumblers I! are mounted. It will be apparent that as the keyhole is of circular shape thepin tumblers, if of the same diameter throughout,

would drop into the key opening. To prevent this the pin tumblers I! are provided with shoulders l8 which contact with shoulders I8 at the lower ends of the chambers I6. It will be apparent that when the key is not standing in the opening IS, the tumblers will drop downwardly only so far as permitted by contact of the shoulders on the tumblers with the shoulders at the lower ends of the chambers IS.

The key plug is provided at its rear end with a non-circular portion l9, which projects from the rear of the cylinder I0, and mounted on this portion of the key plug is a rollback 20 provided with a non-circular opening 2| to fit the end of the plug. The rollback may be secured in place by screws 22 entering the plug.

As shown more especially in Figs. 2 and 4, the key opening which is circular in shape throughout the greater part of the key plug is continued into the rear end' of the plug which projects beyond the cylinder. At this point, however, the opening is of non-circular shape, and preferably nonsymmetrical with the axis of the keyhole. As shown more particularly in Figs. 4 and 5, the opening l9 at this portion of the plug is substantially of D shape, that is, it may be formed by a circular opening provided with a flat side I!)' at one portion. It will be apparent that if the key were circular in shape and the keyhole of similar shape throughout its length, the key would not serve to rotate the key barrel. However, when the key opening,.or at least a part thereof, is provided with a fiat side, as shown, and the key provided with a similarly shaped end, as will be hereinafter described, a driving relation between the parts will be maintained so that the key plug will be rotated by the key. At the face of the lock the key opening may be provided with a flaring mouth 23 to guide the end of the key into the opening.

I have shown in Figs. 2 and 4 a key 26 which may be employed with my lock. As shown, the bit 25 of this key is circular in cross-section and is provided with a number of annular notches or channels 26 to receive the ends of the pin tumblers l1 and properly align the breaks in the tumblers with the surface of the key plug to permit rotation of the latter. It will be apparent that the over-all diameter of the key is substantially the same as that of the key opening, the slots being milled or otherwise formed in the surface of the key to form circular grooves therein. The portions of the key of original diameter between these slots provide an adequate bearing surface for the key within the keyhole so that there will be no objectionable looseness or play between the parts.

The rear end of the key may be pointed or tapered as shown at 21, which corresponds to the key opening in the rear end of the key plug. Likewise, this part of the key will be provided with a flattened surface 28 corresponding with the flattened surface upon the opening in the key plug, so that the key will fit accurately into this opening in one position of the key and rotate the key barrel.

It will be apparent that the key, being of round shape, may be inserted in the key barrel in any position, and that it will be guided into the opening by the flaring mouth 23 in the key barrel. Moreover, as the ridges between the pin tumbler notches 26 of the key are the same in diameter as the original diameter of the key, they will bear upon the wall of the key opening and guide the key accurately into position. The key may, therefore, be inserted in any position in which it may happen to lie until the rear end 21 reaches the rear portion IQ of the key barrel, the opening in which is non-circular in shape. At this point the key must be rotated until the flat spot upon-it coincides with the fiat portion of the opening in the rear portion of the key barrel, at which time the key may be fully inserted and will operate the lock in the usual manner. It will be noted, however, that this rotation of the key only takes place after the key has been inserted a considerable length into the key opening, and that this rotation is readily accomplished by the feel of the key, and requires only slight attention on the part of the operator.

It will be apparent that there are no ward slots cut into the key bit, and for this reason any round key of the proper size could be inserted into the lock. Such a key would not operate the lock, however, unless it contained the proper pin tumbler notches to align the pin tumblers in the usual manner.

As the use of a circular key reduces to some extent the number of combinations which may be secured with a given number of tumblers in the lock, the number of tumblers may be increased if desired. I have shown six in the embodiment illustrated, but a fewer or greater number may be employed if deemed necessary.

However, the number of lock changes or different combinations may be increased" with my key by changing the shape of the non-circular opening in the rear end IQ of the key barrel. For instance, the fiat spot upon the side of this opening may be made larger or smaller in size, and thus a key, even if circular, could not be used unless the flat spot upon the end of the key 1 corresponded in size with that of the opening in the key barrel. That is, the side l9 as shown in Fig. 5, may be made upon a larger or smaller chord of the circle w and this will, in effect, serve as a ward requiring a key of the proper shape to be employed.

In Fig. 6 of the drawings I have shown a key 38 of somewhat modified form. The bit of this key is circular in shape, as shown at 3|, and the pin tumbler notches may be milled across one side of the key only, as shown at 32, instead of eing annular grooves, as is the case with the key 24. This key is also provided with a tapered end 33 and a flat side 34 corresponding to these parts upon the key 24. When this key is used,

it will be necessary to position the flat side l9 of the rear end of the key opening at the proper place about the circumference of this opening, so that when the rear end of the key registers with this portion of the key opening, the notches 32 will be aligned with the pin tumblers. In this case the notches 32 will not have to be continued entirely around the key, and hence may, if desired, be cut deeper with the same size key bit than would be possible if they were circular grooves, as shown in Figs. 2 and 4.

Moreover, when the key 30 is employed, the fiat side i9 may be placed at different circumferential positions around the opening in the key barrel, and this will provide further key changes as the fiat side 34 must correspond and must be so placed that the notches 32 will be aligned with the pin tumblers when the key is fully inserted. It will be seen, therefore, that no key would operate the lock unless the flat side 34 upon the key and the fiat side l9 upon the wall of the keyhole were properly spaced to align the notches with the pin tumblers. At the same time, the key may be initially inserted in any position within the key barrel, and after it has been inserted nearly its full length, may be rotated until the rear end 33 is in position to enter the rear end of the opening in the key barrel.

In Figs. 7 to 9 of the drawings I have shown a modified form of my invention wherein the interior of the key barrel and the key are provided upon certain portions thereof with special configurations, such as grooves and ridges, for example, which provide wards which will prevent the use of any key other than that having the proper configuration to fit the lock, in addition to having the proper pin tumbler notches therein. The lock shown in Figs. 7 to 9 is in general similar to that shown in Figs. 1 to 5, and the corresponding parts are similarly numbered. It will be noted, however, referring more particularly to Figs. 7 and 9, that the flat side of the non-circular opening H3 in the key plug is provided with ridges or ribs 40 and M, and referring particularly to Fig. 10, it will be seen that the flat side 34 of the key is provided with complemental grooves 42 and 43 to receive the ribs upon the key barrel. The key shown in Fig. 10 is otherwise similar to the key 3|, shown in Fig. 6, in that the notches are out only across one side thereof. They may, however, be cut entirely around the key, and the ward grooves provided upon the fiat inner end of the key in this case as well.

It will be apparent that the ridges 4B and ll may be made of varying widths and may be spaced various distances apart so as to provide in conjunction with the pin tumblers almost any number of key changes that could possibly be employed.

By the above arrangement I have provided in both forms of my invention a key of circular shape which may be inserted in the key barrel in any position, and have also provided an arrangement to eifect the rotation of the key barrel by the key, and at the same time provide for the warding of the keys so that even two keys having the same notches cut in the bit may not always operate a given look. In other words, my key has all the advantages of the usual fiat key, and has the additional advantage that it may be inserted in the key opening in any position.

The key may be made of very light material, such as duralumin, so that it will be very light, and also possess good wearing qualities. Also, the pin tumblers may be made of berylliumcopper or material having a high content of phosphor-bronze, so that the lower rounded ends of the tumblers may be turned and burnished at the same operation, and afterward treated for hardness, and made in this manner the lower ends of the pins will be very smooth and will be equivalent to balls, sometimes used below the pin tumblers of locks.

While I have shown some preferred embodiments of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the appended claims.

What I claim is:

1. A pin tumbler lock comprising a casing an a key barrel rotatably mounted therein, said key barrel having a key opening of circular shape for the greater portion of its length, the rear end of said opening being non-circular in cross-section, and ward elements provided upon the wall of the key opening in said non-circular portion thereof.

2. A pin tumbler lock comprising a cylinder, a key barrel rotatably mounted in the cylinder and projecting therefrom at its rear end, cooperating pin tumblers carried by said cylinder and key barrel, a rollback carried by the projecting end of the barrel, said barrel having a key opening therein, said opening being circular in cross-section from its front end to a point adjacent the rear end of the barrel to permit partial insertion of the key in any position with respect to the longitudinal axis of the opening, and the remainder of said key opening being longitudinally tapered and non-circular in cross-sectional shape to permit full insertion of the key in one position only thereof.

3. A pin tumbler lock comprising a cylinder, a key barrel rotatably mounted in the cylinder and projecting therefrom at its rear end, cooperating pin tumblers carried by said cylinder and key barrel, a rollback carried by the projecting end of the barrel, said barrel having a key opening therein, said opening being circular in cross-section from its front end to a point adjacent the rear end of the barrel to permit partial insertion of the key in any position with respect to the longitudinal axis of the opening, and the remainder of said key opening being of segmental shape in cross-section and longitudinally tapered to permit full insertion of the key in one position only thereof.

4. A pin tumbler lock comprising a cylinder, a key barrel rotatably mounted in the cylinder and projecting therefrom at its rear end, cooperating pin tumblers carried by said cylinder and key barrel, a rollback carried by the projecting end of the barrel, said barrel having a key opening therein, said opening being circular in cross-section from its front end to a point adjacent the rear end of the barrel to permit partial insertion of the key in any position with respect to the longitudinal axis of the opening, and the remainder of said key opening being longitudinally tapered and being of D shape in cross-section to permit full insertion of the key in one position only thereof.

GEORGE B. PICKOP. 

